Research progress on the anti-aging effect of polysaccharides of traditional Chinese medicine: Using Caenorhabditis elegans as an animal model.

With the growing elderly population and increasing incidence of various aging-related diseases, the scientific community is faced with an urgent challenge to identify natural anti-aging agents. Traditional Chinese medicine (TCM) polysaccharides have been proven to have good anti-aging activities. This article reviews the literature on the anti-aging pathways of traditional Chinese medicine polysaccharides applied to Caenorhabditis elegans models in the past decade.

High Resolution Mass Spectrometry Fragmentation Rules of Etomidate and Its Structural Analogues.

Objectives: To explore the characteristic fragment ions, ion abundance ratios and mass spectrometry fragmentation rules of etomidate and its structural analogues by using gas chromatography-quadrupole/orbitrap mass spectrometry (GC-Q/Orbitrap MS) and liquid chromatography-linear ion trap quadrupole-orbitrap mass spectrometry (LC-LTQ-Orbitrap MS) techniques, providing important data support for the identification and prediction of etomidate structural analogues.

Methods: GC-Q/Orbitrap MS and LC-LTQ-Orbitrap MS were used to analyze metomidate, etomidate, isopropoxate and propoxate, to obtain their GC high resolution mass spectra and LC high resolution mass spectra.

Results: Under the electron impact (EI) ion source mode, etomidate, metomidate and the other two analogues all produced their molecular ions and seven identical fragment ions ( 77.

Research Progress on the Application of MALDI-MSI in Hair Analysis.

Mass spectrometry imaging (MSI) is an emerging high-tech "photography" method combining mass spectrometry and image visualization technologies, which can simultaneously monitor the spatial distribution of multiple molecules in biological samples. In recent years, the characteristics of this technology have been used to visually study the distribution of drugs in hair, among which matrix-assisted laser desorption ionization-mass spectrometry imaging(MALDI-MSI) technology has been most widely applied in hair analysis. Based on the principle of MALDI-MSI technology, this paper discusses the key technical elements of MALDI-MSI technology applied to hair analysis and reviews the research achievements of MSI in hair analysis.

Copper-Catalyzed Dynamic Kinetic Asymmetric Arylation of Secondary Phosphine-Boranes for the Synthesis of P(III)-Stereogenic Centers.

Transition-metal-catalyzed asymmetric C-P(III) bond formation is a direct method for the construction of P(III)-stereogenic centers; however, achieving high enantioselectivity remains a challenge. Herein, an unprecedented Cu-catalyzed dynamic kinetic resolution of secondary phosphine-boranes was successfully developed. This asymmetric C-P(BH) coupling reaction provided the direct and highly enantioselective synthesis of P(III)-stereogenic centers, enabling the formation of chiral medium-sized benzophosphine-boranes (7-10-membered cycles).